The conversion of low-price acetone (dimethyl ketone, DMK) by self-condensation process to high-value fine chemicals such as methyl isobutyl ketone (MIBK), diisobutyl ketone (DIBK), phorone (PH), and α-isophorone (IPH) is a challenge that is currently being faced by the industries.
MIBK is an important product derived from acetone. Methyl isobutyl ketone (MIBK), for instance, is a product widely used as a solvent in liquid-liquid extraction, vinyl, epoxy and acrylic resin production, dyes and nitrocellulose production. MIBK is also used as an extracting agent for antibiotic production or removal of paraffins from mineral oils, in the synthesis of rubber chemicals, and in fine chemistry applications. It is used as a solvent in paint and protective coating systems. MIBK is commercially produced using a three-step process. The main reaction pathways for the synthesis of MIBK from acetone are shown in FIG. 1. The first step is the aldol addition of acetone to diacetone alcohol (DA, 4-hydroxy-4-methyl-2-pentanone). The second step is the aldol condensation of DA to mesityl oxide (MO, 4-methyl-3-penten-2-one). The final step is the selective hydrogenation of the carbon-carbon olefinic bond of MO to form MIBK. The most commonly observed side reactions are over-condensation and unselective hydrogenations.
Numerous composite catalyst are currently used in gas or liquid phase production of MIBK to obtain high yield with little success. The production processes are complicated and operational costs are high. The use of homogeneous liquid base and acid composite catalyst create a corrosive environment, require an additional neutralization process for their disposal, and generate a significant wastewater stream. Furthermore, the separation of DA and MO is mandatory for carrying out its successive step. Thus, there is a need for a better composite catalyst, which may be used in gas-phase production as well as in liquid phase production of MIBK. The MIBK production should provide a higher yield and, in turn, should become cost effective.